It has recently been discovered that prokaryotes can acquire resistance to viruses and plasmids by integrating short fragments of foreign DNA into clusters of regularly interspaced short palindromic repeats (CRISPR's). These repeats are then transcribed and processed into small guide RNA's that are used to direct the destruction of foreign nucleic acid. This mechanism has many parallels with eukaryotic RNA interference but the proteins that are associated with the CRISPR response are evolutionarily unrelated to their eukaryotic counterparts. Our long-term goal is to understand the biochemical and structural basis of CRISPR-mediated resistance in prokaryotes. The objective here is to determine the mechanism by which an effector protein, responsible for the ultimate destruction of the foreign invader, is recruited specifically to foreign DNA. Our objective will combine biochemical, structural and cell based experiments. Successful completion of the proposed studies is significant because it will increase our understanding of bacterial resistance to viruses and plasmids. Both of these genetic elements play important roles in the genetics of pathogenic bacteria.

Public Health Relevance

The proposed research is relevant to public health because it will increase our understanding of how pathogenic bacteria protect themselves from invasion by mobile genetic elements, such as viruses and plasmids. This is important because invasion by these elements is a major route by which bacteria acquire antibiotic-resistance and greater virulence. Thus, the proposed research is relevant to the NIH's goals of improving the control of disease, enhancing human health and advancing our understanding of biological systems.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM097330-07
Application #
9355640
Study Section
Macromolecular Structure and Function B Study Section (MSFB)
Program Officer
Bender, Michael T
Project Start
2011-08-15
Project End
2020-06-30
Budget Start
2017-07-01
Budget End
2018-06-30
Support Year
7
Fiscal Year
2017
Total Cost
Indirect Cost
Name
Johns Hopkins University
Department
Biochemistry
Type
Schools of Public Health
DUNS #
001910777
City
Baltimore
State
MD
Country
United States
Zip Code
21205
Singh, Digvijay; Wang, Yanbo; Mallon, John et al. (2018) Mechanisms of improved specificity of engineered Cas9s revealed by single-molecule FRET analysis. Nat Struct Mol Biol 25:347-354
Singh, Digvijay; Mallon, John; Poddar, Anustup et al. (2018) Real-time observation of DNA target interrogation and product release by the RNA-guided endonuclease CRISPR Cpf1 (Cas12a). Proc Natl Acad Sci U S A 115:5444-5449
Johnson, Kaitlin; Bailey, Scott (2017) Microbiology: The case of the mysterious messenger. Nature 548:527-528
Kuznedelov, Konstantin; Mekler, Vladimir; Lemak, Sofia et al. (2016) Altered stoichiometry Escherichia coli Cascade complexes with shortened CRISPR RNA spacers are capable of interference and primed adaptation. Nucleic Acids Res 44:10849-10861
Hayes, Robert P; Xiao, Yibei; Ding, Fran et al. (2016) Structural basis for promiscuous PAM recognition in type I-E Cascade from E. coli. Nature 530:499-503
Estrella, Michael A; Kuo, Fang-Ting; Bailey, Scott (2016) RNA-activated DNA cleavage by the Type III-B CRISPR-Cas effector complex. Genes Dev 30:460-70
Chen, Hongfan; Bailey, Scott (2016) Structural biology. Cas9, poised for DNA cleavage. Science 351:811-2
Mallon, John; Bailey, Scott (2016) A molecular arms race: new insights into anti-CRISPR mechanisms. Nat Struct Mol Biol 23:765-6
Ramachandran, Anita; Bailey, Scott (2016) Memory Upgrade: Insights into Primed Adaptation by CRISPR-Cas Immune Systems. Mol Cell 64:641-642
van Erp, Paul B G; Jackson, Ryan N; Carter, Joshua et al. (2015) Mechanism of CRISPR-RNA guided recognition of DNA targets in Escherichia coli. Nucleic Acids Res 43:8381-91

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